The present invention relates to a golf club head having a hollow structure, and more particularly to a golf club head with a lowered center of gravity which is capable of ensuring shot stability.
A conventional metal wood golf club has a head main body comprising a metallic sole portion and a metallic outer mold which have been fixed solidly together to form a hollow structure. Furthermore, some long iron golf clubs have similar hollow-structure head main bodies.
In a golf club head having this type of hollow structure, it is regarded as important to lower the position of the center of gravity of the head in order to facilitate ball lift and to increase ball flight distance when striking the ball. In the case of the above-mentioned conventional golf club heads, various means have been adopted to lower the center of gravity, such as increasing the thickness of the sole portion or providing a weight to the inner surface of the sole portion. In addition to lowering the center of gravity as described above, it is also regarded as important in the case of a hollow golf club head to increase the moment of inertia around the head's center of gravity in order to ensure shot stability.
However, although a lower center of gravity has been achieved in conventional golf club heads by means such as increasing the thickness of the sole portion or providing a weight to the sole portion, one side effect of such means has been a reduction in the hollowness ratio of the head main body. Consequently, it has been difficult to increase the moment of inertia around the head's center of gravity which depends upon the sole portion, resulting in an insufficient improvement in shot stability.